A5041530475- Crystal Structures and Properties
- Inorganic Chemistry and Materials
- Advanced Chemical Physics Studies
- 2D Materials and Applications
- Iron-based superconductors research
- Graphene research and applications
- Crystallization and Solubility Studies
- Rare-earth and actinide compounds
- Advanced Condensed Matter Physics
- X-ray Diffraction in Crystallography
- Boron and Carbon Nanomaterials Research
- Machine Learning in Materials Science
- Catalytic Processes in Materials Science
- High-pressure geophysics and materials
- Advancements in Battery Materials
- Solid-state spectroscopy and crystallography
- Superconductivity in MgB2 and Alloys
- MXene and MAX Phase Materials
- Crystallography and molecular interactions
- Chalcogenide Semiconductor Thin Films
- Inorganic Fluorides and Related Compounds
- Perovskite Materials and Applications
- Hydrogen Storage and Materials
- Advanced Battery Materials and Technologies
- Catalysis and Hydrodesulfurization Studies
Université de Lorraine
2016-2025
Centre National de la Recherche Scientifique
2016-2025
Laboratoire des Multimatériaux et Interfaces
2025
Laboratoire de Chimie Théorique
2018-2024
Laboratoire de Physique et Chimie Théoriques
2018-2024
Laboratoire de Cristallographie, Résonance Magnétique et Modélisations
2011-2022
Délégation Centre-Est
2017-2021
Institut Jean Nicod
2017
BP (United Kingdom)
2017
Northwest University
2013-2016
We report on ab initio calculations of the two-dimensional systems ${\text{MoS}}_{2}$ and ${\text{NbSe}}_{2}$, which recently were synthesized. find that is a semiconductor with gap rather close to three-dimensional analog, ${\text{NbSe}}_{2}$ metal, similar analog this compound. further computed electronic structure hexagonal (graphene-like) lattices Si Ge compared them graphene. It found properties related Dirac cone do not appear in case germanium, metallic, contrary silicon, also known...
The implementation of technique for full structural optimizations complex periodic systems in the DFT-PAW package VASP, including volume and shape unit cell internal coordinates atoms, together with a correction that allows an appropriate modeling London dispersion forces, as given by DFT-D2 approach Grimme [Grimme, S. J. Comp. Chem. 2006, 27, 1787], is reported. Dispersion corrections are calculated not only forces acting on but also stresses cell. This permits simultaneous optimization all...
We assess the performance of recent density functionals for exchange-correlation energy a nonmolecular solid, by applying accurate calculations with GAUSSIAN, BAND, and VASP codes to test set 24 solid metals nonmetals. The tested are modified Perdew-Burke-Ernzerhof generalized gradient approximation (PBEsol GGA), second-order GGA (SOGGA), Armiento-Mattsson 2005 (AM05) GGA. For completeness, we also more standard functionals: local approximation, original PBE GGA,...
The calculated quasiparticle band structure of bulk hexagonal boron nitride using the all-electron GW approximation shows that this compound is an indirect-band-gap semiconductor. solution Bethe-Salpeter equation for electron-hole two-particle Green function has been used to compute its optical spectra and results are found in excellent agreement with available experimental data. A detailed analysis made excitonic structures within gap excitons belong Frenkel class tightly confined layers....
The structural properties of graphite, such as the interlayer equilibrium distance, elastic constant, and net layer binding energy, are obtained using adiabatic-connection fluctuation-dissipation theorem in random phase approximation. Excellent agreement is found with available experimental data; however, our computed energy 48 meV per atom somewhat smaller than one by quantum Monte Carlo methods. asymptotic behavior dispersion interaction, previously derived from analytic approximations,...
The structural and elastic properties of orthorhombic black phosphorus have been investigated using first-principles calculations based on density functional theory. parameters calculated the local approximation (LDA), generalized gradient (GGA), with several dispersion corrections to include van der Waals interactions. It is found that improve lattice over LDA GGA in comparison experimental results. reproduce well trends under pressure show interactions are most important for...
The method proposed by Tkatchenko and Scheffler [Phys. Rev. Lett. 102, 073005 (2009)] to correct density functional calculations for the missing van der Waals interactions is implemented in Vienna ab initio simulation package (vasp) code tested on a wide range of solids, including noble-gas crystals, molecular crystals ($\ensuremath{\alpha}$-N${}_{2}$, sulfur dioxide, benzene, naphthalene, cytosine), layered solids (graphite, hexagonal boron nitride, vanadium pentoxide, MoS${}_{2}$,...
Using the GW approximation, we study electronic structure of recently synthesized hydrogenated graphene, named graphane. For both conformations, minimum band gap is found to be direct at $\ensuremath{\Gamma}$ point, and it has a value 5.4 eV in stable chair conformation, where H atoms attach C alternatively on opposite sides two-dimensional carbon network. In metastable boat conformation energy 4.9 eV. Then, using supercell approach, graphane was modified by introducing either hydroxyl group...
When either electron or hole doped at concentrations x approximately 0.1, the LaFeAsO family displays remarkably high temperature superconductivity with Tc up to 55 K. In most energetically stable Q-->M=(pi,pi,0) antiferromagnetic (AFM) phase comprised of tetragonal-symmetry breaking alternating chains aligned spins, there is a deep pseudogap in Fe 3d states centered Fermi energy arising from light carriers (m* 0.25-0.33), and very strong magnetophonon coupling uncovered. Doping (of sign)...
In an effort to find alternatives graphene, researchers have searched a crystallographic database uncover 92 solids that should be easy exfoliate into two-dimensional sheets with potentially useful electronic properties.
Dehydration of the hybrid compound [Ni3(OH)2(tp)2(H2O)4] (1) upon heating led to sequential removal coordinated water molecules give [Ni3(OH)2(tp)2(H2O)2] (2) at T1 = 433 K and thereafter anhydrous [Ni2(OH)2(tp)] (3) T2 483 K. These two successive structural transformations were thoroughly characterized by powder X-ray diffraction assisted density functional theory calculations. The crystal structures new compounds 2 3 determined. It was shown that (433 K) infinite nickel oxide chains built...
We use first-principle calculations to investigate the electronic structure of InSe and In2Se3. The interlayer binding energy is found be in same range as for other 2D systems, monolayers are dynamically stable, which suggest possibility obtain them isolated layers. GW approximation including spin-orbit used bandgaps, relevant application electronics. Also, it shown that an electric field perpendicular layers can induce a semiconductor metal transition this family compounds.
The Tkatchenko–Scheffler method for calculating dispersion correction to standard density-functional theory, which uses fixed neutral atoms as a reference estimate the effective volumes of atoms-in-molecule and calibrate their polarizabilities coefficients, fails describe structure energetics ionic solids. Here, we propose more appropriate partitioning, based on iterative Hirshfeld scheme, where fractionally charged atomic state is determined self-consistently. We show that our new extends...
Recently we have demonstrated that the applicability of Tkatchenko-Scheffler (TS) method for calculating dispersion corrections to density-functional theory can be extended ionic systems if Hirshfeld estimating effective volumes and charges atoms in molecules or solids (AIM’s) is replaced by its iterative variant [T. Bučko, S. Lebègue, J. Hafner, Ángyán, Chem. Theory Comput. 9, 4293 (2013)]. The standard uses neutral as a reference, whereas (HI) scheme fractionally charged atomic reference...
In the current work, we demonstrate that single Cu atoms, which are site-specifically stabilized in Ti vacancy of TiO 2 , interact with surrounding and control overall electronic properties (reducibility defect formation) .
The electronic structure of the superconducting material LaOFeP is investigated by means ab initio calculations using density functional theory. concept two-dimensional building blocks as well Bader analysis are used to obtain more insight about charge transfer in this layered material. band and Fermi surface presented order be compared with future experiments. It found that intralayer chemical bonding present a significant part covalency, whereas interlayer almost completely ionic. Also,...
A new implementation of the GW approximation (GWA) based on all-electron Projector-Augmented-Wave method (PAW) is presented, where screened Coulomb interaction computed within Random Phase Approximation (RPA) instead plasmon-pole model. Two different ways computing self-energy are reported. The used successfully to determine quasiparticle energies six semiconducting or insulating materials: Si, SiC, AlAs, InAs, NaH and KH. To illustrate novelty real imaginary part frequency-dependent...
Chalcogen bonding has been investigated in terms of the electron density distribution ρ(r) around chalcogen atoms. The evolution along series atoms is shown based on ab initio calculations chalcogenophthalic anhydrides C8O2H4Chal (Chal = O, S, Se, and Te), where Chal atom its sp3 hybridization. From a detailed analysis experimental theoretical L(r) −∇2ρ(r) function crystal phase C8O2H4Se, we characterize directionality strength (Se···O Se···Se) hydrogen (Se···H) interactions. In addition,...
We performed a systematic density functional (DF) study of the adsorption copper, silver, and gold adatoms on pristine graphene, especially accounting for van der Waals (vdW) interactions by vdW-DF PBE + D2 methods. In particular, we analyze preferred site (among top, bridge, hollow positions) together with corresponding distortion graphene sheet identify diffusion paths. Both vdW schemes show that coinage metal atoms do bind to in some cases buckling layer can be significant. Only results...
We propose a new class of materials, which can be viewed as graphene derivatives involving Group IA or VIIA elements, forming what we refer to graphXene. show that in several cases large band gaps found open up, whereas other semimetallic behavior is found. Formation energies indicate under ambient conditions, sp$^3$ and mixed sp$^2$/sp$^3$ systems will form. The results presented allow us by careful tuning the relative concentration adsorbed atoms, it should possible tune gap graphXene take...
The energy and gradient expressions for the many-body dispersion scheme (MBD@rsSCS) of Ambrosetti et al (2014 J. Chem. Phys. 140 18A508) needed an efficient implementation method systems under periodic boundary conditions are reported. is expressed as a sum contributions from points sampled in first Brillouin zone, close analogy with planewave implementations RPA electrons dielectric matrix formulation. By avoiding handling large supercells, considerable computational savings can be achieved...
During the past two decades, density-functional (DF) theory has evolved from niche applications for simple solid-state materials to become a workhorse method studying wide range of phenomena in variety system classes throughout physics, chemistry, biology, and science. Here, we review recent advances DF calculations modeling, giving classification modern DF-based methods when viewed modeling perspective. While progress been very substantial, many challenges remain on way achieving consensus...
By explicitly including fractionally ionic contributions to the polarizability of a many-component system, we are able significantly improve on previous atom-wise many-body van der Waals approaches with essentially no extra numerical cost. For nonionic systems, our method is comparable in accuracy existing approaches. However, it offers substantial improvements solids, e.g., producing better polarizabilities by over 65% some cases. It has particular benefits for two-dimensional transition...
By means of first-principles $GW$ calculations, we have studied the electronic structure properties $M{X}_{2}$ ($M=\text{Mo}$, W; $X=\text{S}$, Se, Te) bilayers, including hybrid structures building blocks. The effect spin-orbit coupling on and van der Waals interaction geometry were taken into account. All homogeneous bilayers are identified as indirect band-gap materials, with an increase band gap when Mo is changed to W, a decrease atomic number $X$ increased. same behavior also observed...